I'm hoping someone may help.  The inside of our toilet cistern including the 
fittings are covered in black mould, there is even a line around the water 
rim. I have used bleach in the past to clean it but cannot work out what is 
causing it, there is no damp in the bathroom and plenty of ventilation. The 
cistern is a porcelin type/ceramic inside and I never had this problem with 
my last one. This one has only been fitted 3 years - would replacing the 
plastic fittings inside with better quality ones help?
Any advice, most appreciated.

In article <diqvk9$k1u$1@newsg2.svr.pol.co.uk>,
	"Moon~Shadow" <Moon~Shadow@ITpersian1995.freeserve.co.uk> writes:

> I'm hoping someone may help.  The inside of our toilet cistern including the 
> fittings are covered in black mould, there is even a line around the water 
> rim. I have used bleach in the past to clean it but cannot work out what is 


Bleach is not a cleaner, it just makes the dirt colourless so
you can't see it.  You could try using a proper cleaner and
brush to remove whatever the mould is growing on.

Where does the water supply come from? I'm wondering if it's
contaminated with some organic matter. If it comes from a loft
tank, you might want to check that's clean.

-- 
Andrew Gabriel